1. Sticking with cartridges for the N64
A fairly well-covered one you might be thinking and you'd be correct. Nintendo had their reasons for sticking with the increasingly dated cartridge format but in hindsight, this was a huge mistake. Nintendo immediately lost Squaresoft and in turn the important Final Fantasy franchise to Sony when the increased storage space, superior audio and greater capacity for cutscenes offered by the CD-ROM format proved to be the only way for them to realise Final Fantasy VII - a game which went on to be a genuine system seller for Sony. Whoops. Other developers/publishers would decide similar and so Nintendo was left to rely on the strength of its first party titles and third party exclusives which thankfully turned out a number of milestones during the N64's lifespan that are still regarded highly to this day. The N64 was in no way a failure that shamed Nintendo but clearly it was the beginning of Nintendo's disconnect with the gaming public and their evolving tastes - tastes that Sony and (later) Microsoft would gladly cater for much to Nintendo's loss. Still, the N64 didn't fare as badly as Sega's 32-bit offering...
2. Their handling of recent Limited Editions
I've had a few heavy rants about this situation recently so I won't go on about it too much more but this is a serious issue for me. When Nintendo chronically underproduce their special boxsets it a) annoys the thousands of fans left without a copy b) plays into the hands of dirty, profit-grabbing re-sellers (the Fire Emblem Fates EU LE is listed on Amazon for £218.00 at the time of typing this!!!!!!) and c) means that Nintendo miss out on making even more profit for themselves, something I would have thought essential in their current situation with the Wii-U performing so dismally. Speaking of which...
3. The Wii-U
Let's get one thing down straight away: I love my Wii-U. I love the games available for it, I love the innovative nature of the Gamepad and I love its flawless backwards-compatibility. However, it has done Nintendo some serious damage that won't easily be fixed. I was in no way surprised when Nintendo failed to capture the lightning bottled during the Wii's dominant reign but nobody could have predicted just how poor its successor would be. The name alone confuses people, it is virtually anonymous on the high street and third party support is limited to niche or core games that surely don't make any business sense for their respective publishers. I can't stand the likes of FIFA or Call of Duty but the fact is, if your console doesn't have these games, it will sell poorly and be dismissed by a rather important chunk of the target audience. Regardless, Nintendo barely promoted this thing. I hardly saw any advertising for the games post-launch and have had to rely on forums or chat amongst gamers just to know what is on the horizon. It's almost as if Nintendo saw the initial flop and decided to just leave the Wii-U to die. No agressive advertising or attempts to turn things around. Nothing. What a disaster.
4. No 'proper' Pokemon for Wii or Wii-U
Surely I wasn't the only one completely baffled by the lack of a proper Pokemon game on a home console? Did nobody else envisage an online/offline MMO game in the style of the handheld quests but in full 3D with online battling/trading? It would be a sure-fire way of tapping into the rabid Pokemon fanbase (of which I was once very much a part of) and shifting a load of hardware. I for one bought a Gamecube just because Pokemon Coliseum was on it and subsequently ended up with a large collection of non-Pokemon Gamecube games. Coliseum and XD: Gale of Darkness weren't proper Pokemon games though and the Wii only received the glorified 3D battling game known as Battle Revolution. Surely the Wii-U was in desperate need of a real Pokemon installment? If the NX doesn't host such a game then I'll be beyond questioning Nintendo's decision makers.
5. Not including chargers with 3DS XL
Now why on earth would you do this? It's like buying a car and having to purchase the alternator separately so that you have something to recharge the battery with...something that should just be included as standard! I have very little to say about this because it is that ridiculous. Obviously the justification was either to save money or because they believed potential buyers would already own the standard 3DS and not need a charger. Well, the first reason is just cheap and also flawed since we know Nintendo actually makes a profit on its hardware (unlike rivals) so an AC adaptor is hardly going to ruin that bottom line. As for the second (possible) reason, will'ya think about the new 3DS buyers who know nothing about this system and wouldn't expect there to NOT be a charger? Apparently the US gets a charger with their console whereas Europe doesn't. Europe getting shafted by Nintendo; haven't heard of that one before. Nope.